Fork lift truck load support carrier



Aug. '18, 1959 J. R. FORREST, ET AL 2,900,098

FORK LIFT TRUCK LOAD SUPPORT CARRIER 2 Sheets-Sheet 1 Filed Nov. 12,1957 INVENTOR S R. FORREST MOUL JOHN

ALBERT A.

Aug. 18, 1959 R FORRE5T ETAL 2,900,698

FORK LIFT TRUCK LOAD SUPPORT CARRIER Filed Nov.

2 Sheets-Sheet 2 United States Patent FORK LIFT TRUCK LOADSUPPORT'CARRIER 1 John R. Forrest, Vancouver, British Columbia, andAlbert A. Moul, Burnaby, British Columbia, Canada, assiguors toMacMillan & Bloedel Limited, Vancouver, British Columbia, Canada, acorporation of British Columbia, Canada Application November 12,1957,Serial No. 695,811

11 Claims. Cl. 214-650) This invention relates to. a loadsupport carrierfor fork lift trucks and the like.

Lumber is usually piled in groups or bundles constituting a load thatmay be lifted by a fork lift carrier or other means. The load is placedon suitable supporting means, such as spaced blocks or strips of wood,so that the forks of a lift truck may be moved beneath the bundle inorder to pick it up and transport it to some other place. When the loadis to be deposited, supporting strips or blocks are first laid down andthen the load placed on them. This is done even if a load is placed ontop of another load. This involves the necessity of men shifting thesupporting blocks with the constant possibility of inury.

The present invention eliminates the necessity of having men move thesupporting blocks for the lumber loads or bundles. Each load of lumberis placed on a support which may be in the form of one or more carrierblocks. When it is desired to lift the load, the lift truck is moved sothat its forks are, positioned beneath the load in the usual manner. Theload support carrier is so designed and mounted on the lift truck thatwhen the forks are raised to lift the load, the carrier grips the loadsupport and lifts it beneath the load. When the load is moved towardsthe ground, the support rests on the ground first and then the load isdeposited on it. Thus, the load support is always with the load, andthere is no necessity for anyone to go near the load when it is beinglifted or deposited.

Although this apparatus is particularly designed for lumber loads and isso described herein, it will be understood that it may be used withother types of load as well.

Fork lift trucks have substantially vertical lifting frames with forksat the bottoms thereof projecting outwardly therefrom. These frames aremovable from and to lower positions where the forks are near the ground.

The load support used with this invention may be of any desired shapeand construction provided that it has a projecting part spaced above theground and will allow forks of the truck to be moved beneath the loadbeing supported. g

A load support carrier according'to the present invention comprisespick-up means mounted on the lifting frame of a lift truck for limitedvertical movement on said frame near the forks thereof, and stop meansmounted on the frame spaced above the pick-up means. When the forks aremoved beneath the load on the support, the pick-up means is movedbeneath the projecting part of the support. As the lifting frame of thetruck is raised, the forks lift the load and the pick-up means pressesthe support against the stop means to raise the support with and beneaththe load. Although not absolutely necessary, it is desirable to providemeans connected 'to'the stop-means for moving the latter towards andaway from the pick-up means. When this moving means is provided, thestop means may be moved to press the load support against the pick-upmeans firmly to grip said support.

.inner or movablesection 26 of the tower.

An example of this invention is illustrated in the accompanyingdrawings, in which,

Figure 1 is a perspective view of one form of load support that may beused with this invention,

Figure 2 is a side elevation of the front portion of a fork lift truck,showing the load support carrier in side elevation, the forks of thetruck being in their lowermost position beneath a load which is shown inbroken lines,

Figure 3 is a fragmentary view similar to Figure 2, but showing theforks elevated from the ground,

Figure 4 is a front elevation of the load support carrier and the lifttruck, with the prongs in their lowermost position, and

Figure 5 is a horizontal section through the load support carrier takensubstantially on the line 5-5 of Figure 4.

Referring to Figure 1 of the drawings, 10 is one form of load supportthat may be used with this invention. This support has a top 12withblocks 13 and 14 near and spaced inwardly from the ends thereof tosupport the top above the ground. One or both ends of the top projectoutwardly, as indicated at 15 and 1 6. I

Support 10 may be large enough to carry the entire load itself, in whichcase, blocks 13 and 14 will have to be' positioned so that the forks onthe lift truck may be moved beneath top 12. However, in ordinarypractice, these supports are comparatively narrow and two or more ofthem are spaced apart and placed beneath the load, in which case, thetruck forks move beneath the load at points where there are no supports.

Referring to Figures 2 to 5, 20 diagrammatically illustrates aconventional fork lift truck having a substantially vertical liftingtower'21 pivotally mounted at its lower end at 22 thereon. This towerhas the usual stationary section 25 which slidably supports an innersection 26 that is movable vertically relative to the stationarysection. Suitable means generally designated by the numeral 28 areprovided for tilting the tower back and forth in the customary manner;

Fork lift trucks have lifting frames mounted on the towers thereof, saidframes having forks projecting outwardly from them and from the truck.Truck 20 may have a standard lifting frame thereon to which are attachedthenecessary elements to form the present invention. The illustratedload support carrier is mounted on a lifting frame 30 which is slidablymounted for vertical movement on the tower 21 in the usual manner. Asthe mounting of this'frame does not form part of the invention, and iswell known in the art, it does not need to be described herein. It issufficient to say that a vertical hydraulic cylinder 33 is mounted atits lower end on the tower near the bottom thereof and projects upwardlywithin said tower. A ram 34 slidably extends outwardly from the cylinderand is connected at its upper end to a crosshead 35, said head beingconnected at 36 to the A pair of sprockets 38 and 39 are rotatablymounted on the crosshead, and chains 40 extend over these sprockets. Oneend of each chain is anchored at 42 to the stationary section 25 of thetower, while the opposite end of said chain is anchored at 43 to a bar44 which constitutes part of frame 30 and projects inwardly from saidframe towards the tower, see Figure 2.

With this arrangement, when ram 34 is extended from cylinder 33, theinner section 26 of the tower is raised, sprockets 38 and 39 movingtherewith. As the inner ends of chains 40 are anchored to the stationarysection of the tower, the outer ends 43 thereof move upwardly drawinglifting frame 30 with them. This action is reversed when the ram isretracted. The controls for the hydraulic cylinder have been omitted forthe sake of clarity.

Frame 30 is provided with a lower bar 48 extending parallel to bar 44,and it has spaced vertical supporting plates 49 and 50 secured at theiropposite ends to said bars. Channel-shaped-standards 53 and 54 aresecured to the outer ends of the upper and lower bars 44 and 48, andproject upwardly above the latter, as clearly shown in Figure 4. i

A pair of forks 57 and 58 are secured to frame 30 in any desired manner.Forks 57 and 58 have vertical portions 60 and 61, and horizontalportions 62 and 63, respectively. In this example, horizontal shafts 65and 66 are carried by standard 53 and support 49, and standard 54 andsupport 50, respectively. Shaft 65 extends through the vertical portion60 of fork 57, while shaft 66 extends through the vertical portion 61 offork 58. The vertical portions of the forks extend downwardly over andbear againstlower bar 48 of the lifting frame.

Pick-up means is provided on lifting frame 30 for limited verticalmovement thereon near the forks 57 and 58 thereof. In the illustratedform of the invention, this pick-up means comprises a shoe 74 whichextends the full width of and beyond the sides of frame 30 near thehorizontal portions of the forks, see Figures 2 to 4; This shoe has ahorizontal base 75 and preferably,valthough not necessarily, a back 76projecting upwardly from this base near the inner edge thereof. Thisshoes is supported adjacent its opposite ends by arms 78 and 79whichextend upwardly beside standards 53 and 54, respectively. As themounting of these arms is exactly the same, one only will be describedin detail. Arm 78 slidably extends through a bracket 81 carried bystandard 53. A spring 82 has one end anchored at 83 to the standard, andits opposite end 84 connected to the upper end of arm 78. Means isprovided for limiting the downward movement of the arm and,consequently, shoe 74. This may be accomplished by a block 86 mountedonthe arm and a set screw 87 threaded through a sleeve 88 carried by thestandard. This set screw may be adjusted to vary the limit of thedownward movement of the block and arm.

As arms 78 and 79 are mounted in the same manner, shoe 74 is suspendedby resilient means (springs 82), from the lifting frame 30. The shoe ispermitted a limited degree of movement relative tothe lifting frame andto the forks thereof.

Stop means is mounted on the frame spaced above the pick-up means orshoe 74. This stop means may be in the form of one or more stop barsmounted above the shoe. In this example, stop bars 95 and 96 arepositioned above the ends of the shoe 74 for this purpose. As these stopbars are mounted in exactly the same manner, only one, namely bar 95,will be described in detail.

The stop bar may be permanently or adjustably mounted at a predetermineddistance above shoe 74. However, it is preferable to provide means'formoving the bar towards and away from the shoe.

Each of the stop bars 95 and 96 is carried by a pair of arms 100 and 101projecting upwardly therefrom and slidably through brackets 102 and 103carried by lower bar 48 of the lifting frame. The upper ends ofthesearms converge inwardly to a common supporting arm 105 which extendsupwardly parallel to the adjacent frame standard. This arm slidablyextends through a bracket 106 carried by the standard, and a hydrauliccylinder 107 is connected to the upper end of the arm at 108. A ram 109slidably projecting from this cylinder is connected at 110 to thestandard. The pipes and controls for this cylinder have been omitted forthe sake of clarity since they are standard equipment in the hydraulicfield. There are, of course, two cylinders 107, .one on each of thestandards 53 and 54. These cylinders may be operated to move stop bars95 and 96 towards and away from s hoe, 74. These stop bars are normallyretained in positlon spaced from the shoe.

The operation of this load support carrier is relatively simple, Aspreviously stated, the load, indicated in broken lines at 115 in Figures2 and 3, is placed on a plurality of spaced and substantially parallelload supports 10. When it is desired to pick the load up, the forks 57and 58 of the truck 20 are moved to their lowermost positions, and thenthe truck is moved to insert the forks beneath the load on the supportsor blocks, see Figure 1. At this time, shoe 74 is moved beneath theprojecting ends 15 of the supports. Then the lifting frame 30 is movedupwardly by means of cylinder 33 to cause the forks to lift load 115.-As the frame and forks move upwardly, the shoe is moved against theunder surfaces of the support projections, but the springs 82 preventthe shoe from lifting the supports until the forks have taken the fullload. Atthis time, blocks 86 of arms 78 have moved into engagement withset screws 87 so that the shoe moves upwardly with the lifting frame.

As previously stated, stop bars and 96 may be set in fixed predeterminedpositions about the level of shoe 74. If this is the case, the shoewould lift the support projections against the stop bars to gripsaid-projections. However, it is preferable to provide the cylinders 107so that the operator of the truck can cause said cylinders to move thestop bars downwardly against the upper surfaces of the load supportprojections firmly to grip said projections between the bars and theshoe. As the-lifting frame continues to move upwardly, the gripped loadsupports are lifted with it beneath the load. Therefore, the supportsare never separated from the load, and they remain in their properpositions relative thereto so that when the supporting frame is moveddownwardly the supports contact the ground first and then as the forkscontinue to move downwardly, the load is deposited on said supports, thelatter being released by raising the stop bars by means of cylinders107. Thus, there is no need for men to place load supports beneath orremove them from beneath a load during'loading operation of the lifttruck. In other words, the operator of the truck has full control ofboth the load and the supporting blocks therefor during both the liftingand lowering of the load.

What we claim as our invention is:

1. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bottoms thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced baove the ground and is such that the forks canengage a load to lift it off the support, said carrier comprisingpick-up means mounted on a lifting frame for vertical movement relativethereto and located near the forks thereof, said pick-up means when theforks are moved beneath a load on a support being positioned to movebeneath the projecting part of the latter and the relative movement ofthe pick-up means preventing said means from lifting the support duringthe first part of upward movement of the forks to take the load, meanson the frame for stopping downward relative movement of the pick-upmeans when the forks have moved upwardly a predetermined distance, andstop means mounted near but spaced above the level of the pick-up means,whereby the pick-up means presses the projecting part of the supportagainst the stop means firmly to grip said part after theabove-mentioned relative movement has taken place during the upwardmovement of the forks, at which time the support is moved with the loadindependently thereof.

2. A load support carrier as claimed in claim 1 in which the pick-upmeans is resiliently suspended from the lifting frame and retained justabove the ground when the forks are at the ground.

3. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bottoms thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced above the ground and is such that the forks canengage a load to lift it off the support,

. said carrier comprising a pick-up shoe resiliently mounted on alifting frame for vertical movement relative thereto and locatednear theforks thereof, said shoe when the forks are moved beneath aload on asupport being positioned to move beneath the projecting part of thelatter and the relative movement of the shoe preventing said shoe fromlifting the support during the first part of upward movement of theforks to take the load, means on the frame for stopping downwardrelative movement of the shoe when the forks have moved upwardly apredetermined distance, and a stop bar mounted near but spaced above thelevel of the shoe, whereby the shoe presses the projecting part of thesupport against the stop bar firmly to grip said part after theabove-mentioned relative movement has taken place during the upwardmovement of the forks, at which time the support is moved with the loadindependently thereof.

4. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bottom thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced abovethe ground and is such that forks canengage a load to lift it off the support, said carrier comprising apick-up shoe resiliently suspended from a lifting frame and movablevertically relative thereto near the forks thereof, said shoe projectingoutwardly in the same direction as the forks, said shoe when the forksare moved beneath a load on a support being positioned to move beneaththe projecting part of the latter and the relative movement of the shoepreventing said shoe from lifting the support during the first part ofupward movement of the forks to take the load, means on the frame forstopping downward relative movement of the shoe when the forks havemoved upwardly a predetermined distance, and a stop bar mounted near butspaced above the level of the shoe, whereby the shoe presses theprojecting part of the support against the stop bar firmly to grip saidpart after the above-mentioned relative movement has taken place duringthe upward movement of the forks, at which time the support is movedwith the load independently thereof.

5. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bottoms thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced above the ground and is such that the forks canengage a load to lift it off the support, said carrier comprisingpick-up means mounted on a lifting frame for vertical movement relativethereto and located near the forks thereof, said pick-up means when theforks are moved beneath a load on a support being positioned to movebeneath the projecting part of the latter and the relative movement ofthe pick-up means preventing said means from lifting the support duringthe first part of upward movement of the forks to take the load, meanson.

the frame for stopping downward relative movement of the pick-up meanswhen the forks have moved upwardly a predetermined distance, stop meansmounted on the frame near but spaced above the level of the pick-upmeans, and means carried by the frame and connected to the stop meansfor moving the latter towards and away from the pick-up means, wherebywhen the stop means is moved towards the pick-up means the projectingpart of the support is gripped therebetween after the above-mentionedrelative movement has taken place during the upward movement of theforks, at which time the support is moved with the load independentlythereof.

6. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bot toms thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced above the groundand is such that the forks canengage a load to lift it off the support, said carrier comprising apick-up shoe resiliently mounted on a lifting frame for verticalmovement relative thereto and located near the forks thereof, said shoewhen the forks are moved beneath a load on a support being positioned tomove beneath the projecting part of the latter and the relative movementof the shoe preventing said shoe from lifting the support during thefirst part of upward movement of the forks to take the load, means onthe frame for stopping downward relative movement of the shoe when theforks have moved upwardly a predetermined distance, a stop bar mountedon the frame near but spaced above the level of the shoe, and meanscarried by the frame and connected to the stop bar for moving the lattertowards and away from the shoe, whereby when the stop bar is movedtowards the shoe the projecting part of the support is grippedtherebetween after the above-mentioned relative movement has taken placeduring the upward movement of the forks, at which time the support ismoved with the load independently thereof.

7. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bottom thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced above the ground and is such that forks canengage a load to lift it off the support, said carrier comprising apick-up shoe resiliently suspended from a lifting frame and movablevertically relative thereto near the forks thereof, said shoe projectingoutwardly in the same direction as the forks, said shoe when the forksare moved beneath a load on a support being positioned to move beneaththe projecting part of the latter and the relative movement of the shoepreventing said shoe from lifting the support during the first part ofupward move ment of the forks to take the load, means on the frame forstopping downward relative movement of the shoe when the forks have amoved upwardly a predetermined distance, a stop bar mounted on the framenear but spaced above the level of the shoe, and means carried by theframe and connected to the stop bar for moving the latter towards andaway from the shoe, whereby when the stop bar is moved towards the shoethe projecting part of the support is gripped therebetween after theabovementioned relative movement has taken place during the upwardmovement of the forks, at which time the support is moved with the loadindependently thereof.

8. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bottoms thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced above the ground and is such that the forks canengage a load to lift it off the support, said carrier comprising ahorizontal pick-up shoe located near the forks, arms connected to theshoe and extending upwardly therefrom, said arms being slidably mountedon the lifting frame for vertical movement relative thereto, resilientmeans connecting the arms to the frame permitting relative movementtherebetween, said shoe when the forks are moved beneath a load on asupport being positioned to move beneath the projecting part of thelatter and the relative movement of the shoe preventing said shoe fromlifting the support during the first part of upward movement of theforks to take the load, means on the frame for stopping downwardrelative movement of the shoe when the fork have moved upwardly apredetermined distance, a stop bar near but spaced above the level ofthe shoe, an arm connected to the bar and extending upwardly therefrom,said arm being vertically slidable on the frame, and means carried bythe frame and connected to the arm of the stop bar for moving the lattertowards and away from the shoe, whereby when the stop bar is movedtowards the shoe the projecting part of the support is grippedtherebetween after the abovementioned relative movement has taken placeduring the upward movement of the forks, at which time the support ismoved withtheioad independently thereof.

9. A load support carrier for fork lift trucks having substantiallyvertical lifting frame with forks at the bottoms thereof projectingoutwardly therefrom, said frame being movable from' and to lowerpositions where the forks are near the ground, and'the loadsupport has aprojecting part spaced above the ground-and is such that the forks canengage a load to lift it'off the support,- said carrier comprisingsupporting means'carried by and movable with a lifting frame near thebottom thereof and extending laterally therefrom, a substantiallyvertical shoe arm slidably mounted on said supporting means for verticalmovement relative thereto, a substantially horizontal pick-up shoeconnected to and movable with the arm at the lower end thereof, meansresiliently connecting the arm to the supporting means and normallyretaining the shoe substantially at the level of the forks, said shoewhen the forks are moved beneath a loadon a support being positioned tomove beneath the projectingpart of the latter and said relative movementpreventing said shoe from lifting the support during the first part ofupward movement of the forks to take the load, means on the supportingmeans for limiting the downward relative movement of the arm and shoe asthe forks are moved up wardly, and a stop bar mounted on the supportingmeans near but spaced above the level of the shoe, whereby the shoepresses the projecting part of the support'against the stop bar firmlyto grip said part after the above-mentioned relative movement has takenplace during the upward movement of the forks, at which time the supportis moved with the load independently thereof.

10. A load support carrier for fork lift trucks having substantiallyvertical lifting frame with forks at the bottoms thereof projectingoutwardly therefrom, said frames being movable from and to lowerpositions where the forks are near the ground, and the load support hasa projecting part spaced above the ground and -is such that the forkscan engage a load to lift it off the support, said carrier comprisingsupporting means carried by and movable with a lifting frame near thebottom thereof and extending laterally therefrom, a substantiallyvertical shoe arm slidably mounted on said supporting means for verticalmovement relative thereto, a substantially horizontal pick-up shoeconnected to and movable with the arm at the lower end thereof, meansresiliently connecting the arm to the supporting means and normallyretaining the shoe substantially at the level of the forks, said shoewhen the forks are moved beneath a load on a support being positioned tomove beneath the projecting part of the latter and said relativemovement preventing said shoe from lifting the support during the firstpart of upward movement of the forks to take the load, means on thesupporting means for limiting the downward relative movement of the armand shoe as the forks are moved upwardly, a supporting arm slidablymounted on the supporting means for vertical movementthereon, asubstantially horizontal stop bar secured to th e'lower eiidof thesupporting arm and normally spaced "abovethe'level of the shoe, andmeans on the supporting means and connected to the supporting arm formoving the latter arm and the stop bar towards and away from the pick-upshoe, whereby when the stop bar is moved towards the shed the projectingpart of the support is gripped there-between after the abovementionedrelative" movement has taken place during the upward movement of theforks, at which time the support is moved with the load independentlythereof.

11. A load support carrier for fork lift trucks having substantiallyvertical lifting frames with forks at the bottoms thereof projectingoutwardly therefrom, said frames being movable from and tolowerpo'sitions where the forks are near the ground, and the loadsupport has a projecting part spaced above the ground and is such thatthe forks can engage a load to lift it off the support, said carriercomprising supporting means carried by and movable with a lifting framenear the bottom thereof and extending laterally therefrom, asubstantially vertical shoe arm slidably mounted on said supportingmeans for vertical movement relative thereto, a substantially horizontalpick-up shoe connected to and movable with the arm at the lower endthereof, means resiliently connecting the arm to the supporting meansand normally retaining the shoe substantially at the level of the forks,said shoe when the forks are moved beneath a load on a support beingpositioned to move beneath the projecting'part of the latter and saidrelative movement preventing said' shoe from lifting the support duringthe first part of upward movement of the forks to take the load, meanson'the'supporting means for limiting the downward relative movement ofthe arm and shoe as the forks are moved upwardly, a supporting armslidably mounted on the supporting means for vertical movement thereon,a substantially horizontal stop bar secured to the lower end of thesupporting arm and normally spaced above the level of the'shoe, and afluid-operated cylinder mounted on the supporting means and having apiston rod projecting therefromand connected to the supporting arm tomove the'latter'down and up when the cylinder is operated thereby tomove the stop bar towards and away from the pick-up shoe, whereby whenthe stop bar is moved towards the shoe the projecting part of thesupport is gripped therebetwee'n after the above-mentioned relativemovement'has taken place during the upward movement of the forks, atwhich time the support is moved with the load independently thereof.

References Cited in the file of this patent UNITED 'STATES PATENTS

